with the process control system, reducing the complexity of the plant’s automation.

The net result is lower engineering costs, higher machine performance and the elimination of time-critical interfaces between individual components. It also means simple, uniform and transparent programming and diagnostics for the entire machine with a single tool. The greater control over the machine also provides enhanced safety and employee productivity.

As machines come under integrated control, they also require less space. “Physical size reductions are around 15 percent to 25 percent with each product version release,” says Yaskawa’s Faber. “The motor frame size reduction came from the high level of integration between the controller and servo. This evolved as a response to customer needs for one-stop-shopping of motion technology.” He notes that the integration also provides improved safety, start-up ease and improved time-to-market requirements.

Once the machine control is integrated into the overall control system, a manufacturing execution system (MES) system can be used to configure machine operation. “As an MES provider, we also have to provide machine control solutions,” says Torsten Werneke, chief executive officer of Germany-based Itemic. “The MES system has to have a high degree of configurability so you can change the product and change the complete manufacturing line.” Having machine control integrated with MES also lets plant operators map the entire production line and transfer it—with all its efficiencies—to another plant.

Simulating performance

Simulation is also being incorporated into machine control for greater precision and also to allow engineers a simpler programming environment. The simulation has moved beyond prototype testing and into overall production testing. “Simulation is not just computer simulation to build that first prototype,” says Todd Walter, senior product manager for industrial and embedded at National Instruments Corp. (NI), the Austin, Texas-based test and controls vendor. “It takes the algorithms and gets a prototype up and moving in production.”

The integration of the motion control with overall system control also allows the control operator to run simulated tests and work out the bugs before engaging the machine. “Some mechatronic systems require precise motion or machine-control sequences to insure expensive equipment is not damaged from a mis-applied move profile,” says Yaskawa’s Faber. “To prevent unintended crashes, motion-control vendors provide technology to run simulated motion in the control system. This allows the programmer to initiate move sequences from the controller to the servo amplifier through the network without even having a motor attached. The servo amplifier simply feeds back the commanded position as the simulated actual position.”

Using simulation, control engineers can also generate more complex motion profiles. “Simulation software enables the machine OEM (original equipment manufacturer) to develop and test PLC (programmable logic controller) and motion systems at the desk,” says Karl Rapp, segment manager at supplier Bosch Rexroth Corp., in Hoffman Estates, Ill. “The OEM and end-user can verify production cycle times prior to building the machine or production line.”

Reducing power consumption is another goal that drives the integration of machine control with the overall control system. “A lot of the power consumed is used to spin motors. With more motor control, you can design the system to run more efficiently,” says NI's Walter.

As well as controlling the motor, a control system integrated with machine control can help operators determine the most efficient motor for the system. “They’re bringing motor sizing to another level by looking at energy efficiency, heat and volumetric issues,” says Sal Spada, research director, ARC Advisory Group Inc., Dedham, Mass. “They’re completely automating it, so motor selectors are going through a wide range of motor selection.”

With greater technology connecting the machine to control, plant operators are bringing down costs in engineering time as well as energy. The integration also allows for a greater number of sensors that can alert operators to problems before the machine breaks down or slows the line. The machines can also be fine-tuned for improved speed and energy efficiency.

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